6. Hewlett-Packard. What, the world's largest IT vendor sneaks in at only No. 6? Despite a string of software and IT service acquisitions over the past few years, HP is still known more as a PC and printer vendor-hardly strategic stuff. Perhaps HP doesn't get enough credit for the strategic stuff it does; it and IBM (and Oracle-Sun) are the only companies that really do enterprise-class hardware, everything from data center design to disaster recovery planning and management infrastructure. And HP's reputation may start to change if it lands more long-term deals like the one it announced last week with Fortune 1 Royal Dutch Shell, which has tapped HP to develop a wireless sensing system to locate oil and natural-gas reservoirs. Expect HP to move up a future list.

7. Teradata. The smallest among our ranked suppliers, with annual revenue of $1.71 billion (slightly below VMware's $2 billion), this former NCR unit is nonetheless among the most strategic. Marquee customers like Wal-Mart, Coca-Cola Enterprises, eBay, and Overstock.com attribute much of their success to the competitive intelligence they mine through their "partnership" (and that's the word they use most often) with this leading data warehouse and analytics software vendor. Overstock CEO Patrick Byrne, for one, says Teradata "is unbelievably good and has been a big help to us."

8. VMware. EMC treats the No. 1 virtualization software vendor as a separate company, so for the purposes of this ranking so will we. VMware still commands anywhere from 75% to 80% of the hottest enterprise software market, though Microsoft, Citrix, and Red Hat are hot on its heels. Pundits go so far as to speculate that Microsoft and its commoditization of the virtualization market could do to VMware what Microsoft did in a previous generation to the likes of Novell and Netscape. But for now, VMware is king of this strategic sector, and most of its customers are loyal.

9. EMC. Like Cisco in networking, EMC remains almost synonymous with storage, though also like Cisco, its "shop" status doesn't rule out customers going in another direction. Years ago, EMC started acquiring myriad software companies (including VMware) in the event storage would become a commodity, but storage still pays the bills, accounting for 76% of its $14 billion in revenue and a healthy chunk of its profits. (Read Art Wittmann's column, "Practical Analysis: The Storage Stockholm Syndrome," for his analysis of why customers are poised to consider storage alternatives.)

10. Your Outsourcer. This one's a bit of a cop-out, but for a lot of companies, their Accenture or CSC or Wipro or Infosys is their strategic partner-but only if the CIO makes it that kind of relationship.

And now for a couple of vendors that didn't make the cut.

• Dell. No CIO I have interviewed has ever mentioned Dell as among his/her most strategic vendors. Dell, like HP, suffers the Rodney Dangerfield complex, but it's clearly more of a commodity hardware player than HP is. With a series of acquisitions in storage and services, Dell's climbing up the stack-but it's not there yet. But don't count it out.

• Research In Motion. The BlackBerry remains the leading enterprise smartphone, mostly because of the solid management and security features of RIM's BlackBerry Enterprise Server. However, the iPhone is gaining enterprise market share, and leading application vendors, including SAP, Workday, and IBM, are developing for the iPhone first, mostly because of Apple's simpler SDK. In our recent interview with General Motors CIO Terry Kline, he was bullish on developing smartphone apps, but even though the automaker's standard smartphone is the BlackBerry, Kline talked a lot more passionately about Apple and the iPhone. RIM doesn't have the mojo.

Rob Preston,
VP and Editor in Chief, InformationWeek
[email protected]

To find out more about Rob Preston, please visit his page.